As a few of you know, I've been fooling around with some drill holder ideas for awhile. I think I have some that are useable but I would like some more field testing. I am looking for some climbers who actually drill by hand and would be willing to try one out and let me know what happens. It isn't testing if you don't drill holes. No guarantee they will not fall apart or otherwise fail to be useful. You might want to have a backup holder until you are comfortable with it. I don't really like giving them away to just anybody so it would be nice if someone I know or recognize would try them. I'd like them back for postmortem exam.

You'll have to provide your own bits.

So, who, other than yourself, do you nominate to try one out? The nominee should second his own nomination.

These holders are all made by me using the junk machines in my garage.

Clockwise from top in the photo found below:
SDS Medium size with no longer used retainer ring slot (#3)
SDS large size with no longer used retainer ring slot (#2)
A-Taper (#7)
A-Taper (#6)
SDS large size with no longer used retainer ring slot (#1)

#1 has seen some use and has drilled perhaps 10 or more holes either by me or Bob (Cragnshag on ST). Clint has been around these too but I don't recall if he has actually used one. Three other climber friends have versions as well.

I bought one of Dan's current design SDS holders (the "Bayonet") from him, and look forward to using it.
I've broken 2 of the Petzl RockPecker holders - the spring just does not last.
I have a Hurricane also, but Dan's design uses the SDS slot and pocket, so the bit will not loosen up and spin or fall out.
Plus no tool needed to change bits.
And the bit goes deep inside the older, so you can drill on steeper stances without having to swing the hammer back as far.

These free earlier SDS prototypes are the same except they use the retainer ring slot.

How well does this design work for rotating hard (since a lot of the time when you expand a 1/4" hole the bit binds and you really crank on the handle to rotate)? Often you seem to spend more time rotating than hitting, particularly when the old 1/4" was a long one. With Hurricanes the grip sometimes got loose and rotated, the Petzls are better for this in my experience.

On the spring breaking - I've only had one spring break on a Petzl but I hit a lot lighter than most folks.

The main difference between these prototype SDS holders and the final design is that they are made from a softer, low carbon steel. The final versions are made from chromoly steel. They also have the remnants of the old system of retainer ring and washer that used to keep a hot red vinyl grip in place.

what kind of bits fit in each holder. please explain

The three with foam handles hold SDS Plus bits. These are the most common bits and you can find them at the local hardware store.

The longer SDS holder has a deep socket and is intended for 3/8" bits which are typically 6 inches long overall. It will drill a 2.75 or 3 inch deep hole with the typical 3/8" bit. To use a 1/4" bit you will have to buy one that is long enough. A 1/2" bit will not work in this holder.

The medium SDS holder will work with any 3/8" or 1/4" bit. It can be altered to work with a 1/2" bit by drilling out the hole to 1/2" diameter to a depth of about 1/4". I can make this modification pretty easily.

The two little holders use A-Taper bits. I like A-Taper bits because they fit solid and don't wiggle around in the holder. It also results in a holder with no moving parts so failure is pretty unlikely. There is a list of A-Taper bit suppliers in one of the downloads.

How well does this design work for rotating hard

I think you could shear off the torque screws if you put a wrench on it and tried to. So far I haven't had any trouble twisting by hand but I've been drilling new bolts not replacing bolts.

Banquo, TD and I used to use the hex-shaped RAWL holders and loved them because you could slip a ratchet-wrench over the holder and crank that thing around with the ratchet as you were drilling. Man, you can drill fast with the mechanical advantage.

k-man,
The wrench would work on the A-Taper holders. I think a wrench will work on the SDS holders if you can get the wrench past the cable. You could always just cut the cable off. I'm not really sure why I put the cable on since I never use it. The side springs will be in the way at the drill end but I could probably alter the design so it would work.

The A-Tapers have a home, I will send them off to Mucci and John.

I will send one to jaybro but I need to know what he wants.

Klaus can have one but I need to know which one and his address.

Assuming jaybro and klaus want SDS holders, that leaves one more. Clint can have if he wants another.

I have tried and given up on standard HSS twist drill bits. They dull fast, they jam all the time, they are brittle and snap off. I know some swear by them but I've found them more trouble than they are worth.

There are two ways to hold a regular HSS bit. Get a Hurricane drill holder or grind the shank down to match an A-Taper. The Hurricane is a very fine holder but takes two wrenches to change bits. Grinding a drill shank to A-Taper is tricky but can be done if you set up a jig to get the angle right. I can do it fairly well on a benchtop belt sander.

Depending on who you ask, an A-Taper is between 1:20 and 1:20.8. Mine are an included angle of 2.75 degrees which is the 1:20.8. This is based on what the best manufacturers tell me. It's too bad there isn't a standard for A-Taper as the difference between 1:20 and 1:20.8 is enough to cause problems.

Carbide SDS or A-Taper bits usually last a long, long time. They can easily be sharpened with a diamond file. I sharpen new carbide bits and they drill seemingly twice as fast as unsharpened new ones. You can get a set of diamond files on Amazon for less than $10. I did get a batch of carbide bits that shattered after about one and a half holes. The steel at the carbide tip seemed to be too hard and shattered. Other than that they seem to hold up well and can be sharpened many times.

Hey Clint I picked up your new drill from Dan and have it in my garage. You owe me 40 jr. frosties and 40 mcdoubles for it. It is a very nice drill- never hit and only dropped once.

This last weekend I drilled four holes in granite with Banquo's medium SDS holder. The drill feels solid and the size was just right. Bits go in and out with no tool and no hassle. No problems with the holder even though I hit very hard.

On a previous trip I used one of the A-taper holders with a carbide bit and had no issues.

I'm curious what trouble you had with carbide bits. I know I got some bad ones that broke once. They didn't have a manufacturers name so I suspect they were junk I found on eBay. I don't like how long the 3/8" bits are but that is why I put a deep socket in the long version of my holder.

I'm not dissing the hurricane holder. I think it is very good. I've never used one but it seems like 2 wrenches could cause some fumbling when stance drilling.

As far as long SDS bits go, I am contacting manufacturers to see what it would cost to make a runof shorter bits. I may end up with 100 of them and hope other climbers will be interested in getting some.